Bag closure



G. LONG BAG CLOSURE Nov. 22, 1966 5 Sheets-Sheet 1 Filed July 31, 1963 99 FIG. IO

INVENTOR.

GEORGE LONG ATTORNEY FIG.7

N 6 G. LONG 3,286,432

BAG CLOSURE Filed July 31, 1965 5 Sheets-Sheet 2 INVENTOR.

GEORGE LONG ATTORNEY Nov. 22, 1966 G. LONG 3,286,432

BAGv CLOSURE Filed July 51, 1963 5 Sheets-Sheet 5 FIG. l9 FIG. 20

INVENTOR. GEORGE LONG ATTORNEY United States Patent M 3,286,432 BAG CLOSURE George Long, Minneapolis, Minn., assignor to General Mills, Inc., a corporation of Delaware Filed July 31, 1963, Ser. No. 2Q9,033

3 Claims. (Cl. 5338) This invention relates to containers and more particularly to an improved closure for bag-like containers and to a method for accomplishing this closure.

A common packaging problemis that of closing the bag in a manner that the contents thereof are properly sealed within the container. For example, in the packaging of a free-flowing and easily air-borne material such as flour, if there are small leaks or'passages through'the closure portion of the bag, it oftenhappens' that when the bag is moved or stacked, it is pressed or squeezed so as to be subj'ected'to a bellows-like action, with air being pumped in and out of the bag through these small air passages. Theresult is that fineparticles'of the con- 7 tained material are blown out of the bag, this, in the packaging art, being commonly referred to as'sifting.

Aside from this'problem of sitting, there are many other considerations such as economy inthe amount'of bag material used in making the closure, simplifying the steps of accomplishing the closuregm'aking' a neat closure of sufficient strength, bonding 'the'bag' material at the closure 50 that the contained materialis not contaminated by the adhesiveused, arranging the closure and the bag so' that the contents can'be'easily poured embodies to an unusual degree other desirable packaging features, such as those hereinbefore mentioned.

It may also be stated as another object to provide such a closure and method of accomplishing the closure, that 'there is provided a pair of flaps which may be easily joined to form a convenient carrying handle for thebag without detracting from the ends of the aforementioned object. v

Further, it is an object to so arrange the flaps that while the foregoing objects are accomplished, either flap may be cut or torn so as to form a convenient pouring spout.

The closure-provided by the present invention is similar to a well-known and commonly used closure which has long been referred to as the Deltaseal. Because of this, existing bags which are adapted to be closed by the prior art Deltaseal method will usually also be able to be closed according to the present invention. Thus, present packaging operations which are arranged to utilize the Deltaseal closure will, generally speaking, readily lend themselves to be modified so as to incorporate the teachings of the present invention. Thus it may be stated as an additional object of this invention to provide a closure and method of accomplishing the same, the features of which are such that they readily lend themselves to adaptation to existing packaging operations presently using the Deltaseal.

These and other objects and features of the invention will be more readily understood and appreciated from the following detailed description of the preferred em- Patented Nov. 22, 1966 bodiments thereof selected for purposes of illustration and shown in the accompanying drawings, in which: I

FIGURES 1 through 4 illustrate the conventional mannet in which a prior art DeltaseaP closure is accomplished, with FIGURE 4 illustrating the resulting closure; I FIGURES 5 through 8 illustrate a first embodiment of the process of the present invention, with FIGURE 8 illustrating the closure of the present invention which is accomplished by such process; I

FIGURE 9 is a sectional view taken on line 99 of FIGURE 3 and illustratingthe maner in which a conventional"Deltaseal flap is bonded; v

FIGURE 10 is a sectional view taken on line 10-10 of FIGURE 8 and illustrating the manner in which a flap of the present invention is bonded; I

FIGURES 11 through 16 illustrate'afsecond embodiment of the process of the present invention, with FIG- h0g6 at d FIGURES s and 16) are bonded "to the 'bag,'and' Y 1 I.

FIGURES 19 through 21' illustrate the mantle. in

which the flaps ofjthe closure of the present invention maybe bonded one tothe other so as to provide a convenient carrying handle forthe bag. v I

It is believed a clearer understanding offthe' present invention will be attainedby firsfdescribingthe process and end product of the prior art Deltaseal,. and then in light of this disclosure describing the process and end product of the present invention.

The long practiced method by which the conventional Deltaseal closure is accomplished is illustrated in FIG- URES 1 through 4, wherein is shown a bag 10 which has been filled with a material 12 to' the desired level 12a and is now, as illustrated in FIGURE 1, ready to be closed. The bag 10 comprises a body portion 14 which has the general configuration of a rectangular prism and is thus formed with a base (not shown) and four vertical sides 16. The closure portion 18 of the bag 10 is integral with the body 14 and is formed as upward extensions of the four sides 16 above the level 12a to which the material 12 fills the bag 10. This closure portion 18 thus comprises a front, rear and two side walls, designated 20, 22, '24'and 26, respectively, which are joined one to another'by the side portions threof in a generally tubular configuration and which define an upper mouth or top opening 28 through which the material 12 is placed in the bag 10. i

The first step of this prior art process is to apply glue to the inner surface of the upper portions of the rear wall 22 and of the middle and rear portions of the side walls 24 and 26 (the area to which the glue is applied being indicated at 30 in FIGURES 1 and 2). Subsequently (as shown in FIGURE 2) the front wall 20'is folded rearwardly and down along the base portion 20a thereof (i.e., at the top level 12a of the material 12) onto the top of the contained material 12. Then (as shown in FIG- URE 3) the rear wall 22 isfolded forwardly and down in a manner similar to that in which the front wall 18 is folded. --The effect of this is to form each of the side and bonded thereto, the resultant closure being the prior art Deltaseal closure.

One embodiment of the process of the present invention is disclosed in FIGURES 5-8, with the resultant end product (i.e., closure) being illustrated in FIGURE 8. The process of the present invention is, with respect to the manner in which the closure portion of the bag is folded, similar to the prior art Deltaseal process, but differs therefrom primarily in the arrangement in which the various parts of the closure of the present invention are bonded one to another. Consequently, the various portions of the closure of the present invention that are defined by various fold lines created in the closing process are substantially the same as the corresponding portions of the closure of the prior art Deltaseal. Accordingly, the numerical designations used in describing the Deltaseal will be used in describing the present invention, and as the various parts of the present invention are described hereinafter in more detail, the numerical and letter designations applied thereto will (when applicable) also be meant to refer to the corresponding parts of the Deltaseal closure.

Referring now to FIGURE 5, it can immediately be observed that the first embodiment of the process of the present invention differs from the prior art process in that the front wall is folded rearwardly and down from the base 20a thereof prior to the application of adhesive. By so folding the front wall 20, each of the side walls 24 and 26 are folded along a diagonal line reaching from the front wall base line 20a to a point at the top edge of each side wall 24 or 26 moderately behind the mid-length thereof. The resulting folded portion (designated 36) of each side wall 24 or 26 is shaped at a right isosceles triangle, with the hypotenuse edge thereof, designated 360, being the line along which the closure portion 36 is folded. One leg of this triangle 36 is the juncture line at which the front wall20 joins the related side wall 24 or 26 and is designated 36a, while the other leg of the triangle 36 is the middle and front upper edge portion of the related side wall 24 or 26 and is designated 36b.

As illustrated in FIGURE 6, adhesive (glue) is applied to the inner surface of the upper portions of the back wall 22 and of the rear portion of each of the side walls 24 and 26. The adhesive is also applied to the exposed surface of the upper portion of each side wall triangle 36 formed by folding the front wall 20 in the aforedescribed manner. Also, for reasons which will become apparent hereinafter, it"is generally desirable that a certain amount of glue be applied between this upper portion of each triangle 36 and the adjacent portion of its related side wall 24 or 26, this area of application being indicated by the arrow 38.

Subsequent to the application of the glue (the overall area of application being indicated at 40) the rear wall 22 is folded along its base 22a forwardly and down. The effect of this is to fold each of the side walls 24 and 26 along a respective diagonal line 42 reaching from the base 22a upwardly and forwardly to terminate at its related fold line 360 a moderate distance below the upper terminal point of the fold line 360 (this upper terminal point of line 360 being the juncture point of line 360 and line 36b and consequently being designated 36110).

It can be seen that each fold line 42 crosses its related triangular piece 36 near the upper portion thereof and defines with the upper portions of the related lines 360 and 36b a right isosceles triangular piece 44 (this second piece 44 being part of the first fold piece 36) which, when the back wall 22 is folded comes into facing engagement with the adjacent portion of its related langer triangular piece 36. That adjacent portion (which comprises a third piece and is a portion of the triangular piece 36) which so faces the sec-0nd triangular piece 44 has perforce the configuration of a right isosceles triangle congruent with the triangle 44, and is accordingly designated 44'. The hypotenuse sides of triangle 44 and 44 V are designated, respectively, 440 and 44'c; the legs coincident with the aforementioned line 360 are designated 44a and 44a, respectively; and the other leg of each of the triangles 44 and 44' is a common side and hence has the single designation 44b. When the back wall 22 is so folded forwardly and down to form the two side wall folds at 42, the two triangular pieces 44 are each moved so as to form a reentrant fold along line 44b, and the point 44ab of the piece 44 becomes the outermost or apex point of its flap 32 or 34 (this point 44ab being the outer terminal point of fold line 42).

From the foregoing description it is apparent that with both the prior art Deltaseal closure and the closure of the present invention, there is an overlap piece comprising the upper rear wall portion 22b and the adjacent upper rear portions 24b and 26b of side walls 24 and 26, respectively. Also, in both the prior art closure and that of the present invention, there is an underlap piece comprising the upper portion 20b of the front wall 20 and the upper front portion 24c and 26c of, respectively, the side walls 24 and 26, which underlap portion, in both the prior art Deltaseal and the present invention is bonded by its outer surface to the inner surface of the overlap portion, such inner and outer surfaces comprising the bonding area of the closures.

Of particular significance with respect to the problems of the prior art Deltaseal and to the advantages of the present invention is the manner in which there is formed at the outer end of each of the flaps 32 and 34 (in both the prior art and in the present invention) an apex piece, designated generally 46. Each apex piece 46 comprises four portions of its respective side wall 24 or 26, these four portions being the triangular pieces 44 and 44 and two matching triangular pieces 48 and 48' positioned outside of, and adjacent to, respectively, the pieces 44 and 44'.

The manner in which the apex piece 46 of the side wall 26 of the prior art Deltaseal is bonded is illustrated in FIGURE 9. It can be seen that the proximate faces of the inside triangular pieces 44 and 44' of the flap 24 'are not bonded one to another, so that there is formed a passage or opening 50 through which finely divided material contained in the bag 10 can sift from the bag.

, On the other hand, in the present invention, as is illustrated in FIGURE 10, the apex piece 46 of the flap 24 has the two triangular pieces 44 and 44' bonded one to another so as to close the passage 50. If care is taken to bond the extreme outer edge of the overlapping portion 24b (as at 52), and with adhesive being applied only to the opposed faces of the pieces 44 and 44', a sift-proof seal will be effected. However, as a practical matter, it has been found desirable to apply a certain amount of adhesive between the pieces 44 and 48 adjacent the point 36bc, as indicated by the arrow 38, both for added strength and to insure against the possibility of a sift passage being formed at this location, which is indicated in FIGURES 9 and 10 at 53.

It is common in commercial packaging for the bags to be folded fiat when they enter into the packaging operation, and then be mechanically opened prior to being filled with the material to be packaged. To accomplish this, the middle upper edge portion of the side wall 24 is formed with a small cut-out 54 which, when the bag is folded fiat, exposes the inner surface of the corresponding upper middle edge portion 56 of the other side wall 24. This permits a mechanical finger or other member to engage the inner surface of this edge portion 56 and open the bag. When the bag 10 is closed in the aforedescribed manner (either according to the Deltaseal or according to the present invention), this cut-out 54 is formed or located in the triangular piece 44 of the side wall 24. In the prior art Deltaseal closure, this exposes at least part of the glue applied area between the pieces 44 and 48 so as to at least partially obstruct the sift passage 50 and thus diminish the sifting therethrough. However, for the cut-out 54 to serve its bag opening function, the corresponding pieces 56 must b present, which in the prior art, as can be seen by inspecting FIGURE 9, leaves the sift passage 50 fully unobstructed. The present invention, on the other hand, whether the cut-out 54 exists or n0t,-eliminates this problem of sifting.

FIGURES 11-16 illustrate a second and preferred embodiment of the process of my invention. In describing this embodiment, numerical designations will be used similar to those used previously in describing the prior art and the first embodiment of the process of the present invention. In this second embodiment, the bag (shown in open position in FIGURE 11) has its front wall 20 folded rearwardly and down (as shown in FIGURE 12) and then has its back wall 22 fold d forwardly (as in FIGURE 13) so as to form the two triangular side flaps 32 and 34. Desirably, the side flaps 32 and 34 are positioned horizontally (as in FIGURE 14) so as to be in the same plane as the closedtop of the bag 10. Next, the outer edge portion of the overlap piece (22b, 24b, and 26b) is lifted upwardly and glue is applied (as in FIGURE 15) to either or both of the exposed inner surface portions of this overlap piece and the exposed outer surface portion of the underlap piece (b, 24c and 26c). (This area of application is designated 58.) Adhesive is also applied to the exposed surface portion of either or both of the triangular pieces 44 and 44' (as at 60). Subsequently, the overlap and underlap piece are pressed together to form the sift-proof closure of the present invention.

If, While the overlapping piece of the closure portion 16 is lifted (as illustrated in FIGURE 15), the back wall 22 is held firmly along a line extending generally between the end points 44ab of the apex pieces 46, the contents of the bag 10 are effectively isolated from the glue that is applied to either or both the overlap or underlap bonding surfaces. Also, by applying the proper force on each area 61 of each of the overlap portions 24b and 26b at a location adjacent the related triangular piece 44 of each, the area between each apex triangle 44 and its adjacent piece 48 is exposed so that glue may easily be applied in this area as indicated at 62. (It will be recalled that in the previous embodiment of this process, this area of application was indicated by the arrow at 38.) Thus, this second embodiment of the process of the present invention is especially advantageous in that it not only protects the contents of the bag from contamination by the applied glue, but also provides an easy method of exposing both sides of the apex pieces 44 so that both possible sift passages 50 and 53 will be closed by the applied glue.

One manner of securing the flaps 32 and 34 of the present invention (whether formed by the first or second embodiment of this process) is illustrated in FIGURES 17 and 18, where glue is applied over the entire upper surface of each of the flaps 32 and 34, and the flaps then folded over the top of the bag. However, by applying glue only to the upper surface 63 of one of the apex pieces 46, and then bonding the two flaps 32 and 34 together by the apex portions 46 thereof, the two flaps 32 and 34 can be formed into a convenient carrying handle. (This is illustrated in FIGURES 19 through 21.) As disclosed hereinbefore, when the closure portion 16 of the bag 10 is sealed in the manner indicated in either of FIGURES 8 or 16, the bag is already closed in a manner to be siftproof. Hence, the flaps 32 and 34 readily lend themselves to being formed in a handle without detracting from any of the sift-proof qualities of the bag, or if desired, the flaps 32 and 34 can be left in the condition shown in FIGURE 8 or 16 to provide a pair of ears by which the bag may be grasped.

Also, without detracting from the sift-proof features of the bag, it is possible, by cutting one of the flaps 32 6' or 34'be1ow its apex piece 46, to provide a convenient pour spout for the contents 12 of bag 10.

It is believed that while the present process is particularly advantageous with respect to the convenient manner that glue can be applied during the closing process, it is within the broader aspects of the present invention that an adhesive material may be printed on the bags prior to the closure operation. In such a circumstance the bonding may then be accomplished in a suitable manner, as by an application of heat proximate the adhesive coated areas after the bag 10 has been folded to its closed position.

Now, therefore, I claim:

1. A process to close a filled bag at a closure portion thereof, said closure portion comprising front, rear and two side walls which adjoin to one another by the side portions thereof in a generally tubular configuration, each Wall having an inner and an outer surface, each wall also having a base portion by which it joins to said bag and an end portion located opposite its base portion, said process comprising:

(a) folding said front and back wall each along generally the base portions thereof so that each side wall is formed with an upwardly and rearwardly directed first fold lineextending from generally the base portion of said front wall to the end portion of said side wall behind the middle there-of so as to define a respective first triangular fold piece, and each side wall is formed also with an upwardly and forwardly directed second fold line extending from generally the base portion of said back wall to its related first fold line so that each side wall is formed into a flap, at least one of said flaps being thus formed with a reentrant fold adjacent said second fold line, which re-entrant fold forms from an outer portion of said first triangular fold piece a second triangular fold piece, the outer surface of said second piece being in facing relationship to an adjacent portion of said first piece, which adjacent portion comprises a third piece, said back wall overlapping said front wall so that there is provided from said closure portion an underlap piece and an overlap piece, the inner surface of said overlap piece and the outer surface of said underlap piece each being a bonding surface,

(b) lifting from said underlap piece the portion of said overlap piece which is further from the base portion of said back wall, while holding against said underlap piece the portion of the overlap piece which is nearer the base portion of said back wall,

(c) applying an adhesive to at least one of said bonding surfaces and to the outer surface of at least one of said second and third triangular pieces, and bringing said bonding surfaces into contact and bringing into contact said second and third triangular piece so as to bond said underlap piece to said overlap piece and bond said second and third triangular pieces one to another.

2. The process as recited in claim 1, wherein in lifting said overlap piece, the inner surface of said second triangular piece and the inner surface of a side wall portion adjacent to the inner surface of said second triangular portion are moved apart, and adhesive is also applied to at least one of said two last named inner surfaces so that said two last named inner surfaces become bonded one to another.

3. A process to close a filled bag at a closure portion thereof, said closure portion comprising front, rear and two side walls which adjoin to one another by the side portions thereof in a generally tubular configuration, each wall having an inner and an outer surface, each wall also having a base portion by which it joins to said bag and an end portion located opposite its base portion, said process comprising:

(a) folding said front and back wall each along generally the base portions thereof so that each side wall is formed with an upwardly and rearwardly directed first fold line extending from generally the base portion of said front wall to the end portion of tion of said back wall and at the same time applying adhesive to at least one of said bonding surfaces and to the outer surface of at least one of said secnd and third triangular pieces, and bringing said said side wall behind the middle thereof so as to bonding surfaces int-o contact and also bringing into define a respective first triangular fold piece, and contact said second and third triangular piece so as each side wall is formed also with an upwardly and to bond said overlap piece to said underlap piece forwardly directed second fold line extending from and to bond said second triangular piece to said generally the base portion of said back wall to its third triangular piece.

related first fold line so that each side Wall is formed into a flap, at least one of said flaps being thus formed with a re-entrant fold adjacent said second fold line,

References Cited by the Examiner UNITED STATES PATENTS which re-entrant fold forms from an outer portion 2,087,934 7/1937 Anderson 229-62 of sa1d first triangular fold piece a second triangular 2 176 996 10/1939 Leonard et a1 fold piece, the outer surface of said second piece 2271647 2/1942 Kindseth 229*62 being in facing relationship to an adjacent portion of said first piece, which adjacent portion comprises FOREIGN PATENTS a third piece, said back wall overlapping said front 559,832 3/1944 Great Britain wall so that there is provided from said closure portion an underlap piece and an overlap piece, the FRANK E. BAILEY, Primary Examiner.

inner surface of said overlap piece and the outer surface of said underlap piece each being a bonding FRANKLIN GARRETT Exammer' D. M. BOCKENEK, R. L. FARRIS,

surface, (b) holding against said underlap piece the portion Assistant Examiners.

of the overlap piece which is nearer the base por- 

1. A PROCESS TO CLOSE A FILLED BAG AT A CLOSURE PORTION THEREOF, SAID CLOSURE PORTION COMPRISING FRONT, REAR AND TWO SIDE WALLS WHICH ADJOIN TO ONE ANOTHER BY THE SIDE PORTIONS THEREOF IN A GENERALLY TUBULAR CONFIGURATION, EACH WALL HAVING AN INNER AND AN OUTER SURFACE, EACH WALL ALSO HAVING A BASE PORTION BY WHICH IT JOINS TO SAID BAG AND AN END PORTION LOCATED OPPOSITE ITS BASE PORTION, SAID PROCESS COMPRISING: (A) FOLDING SAID FRONT AND BACK WALL EACH ALONG GENERALLY THE BASE PORTIONS THEREOF SO THAT EACH SIDE WALL IS FORMED WITH AN UPWARDLY AND REARWARDLY DIRECTED FIRST FOLD LINE EXTENDING FROM GENERALLY THE BASE PORTION OF SAID FRONT WALL TO THE END PORTION OF SAID SIDE WALL BEHIND THE MIDDLE THEREOF SO AS TO DEFINE A RESPECTIVE FIRST TRIANGULAR FOLD PIECE, AND EACH SIDE WALL IS FORMED ALSO WITH AN UPWARDLY AND FORWARDLY DIRECTED SECOND FOLD LINE EXTENDING FROM GENERALLY THE BASE PORTION OF SAID BACK WALL TO ITS RELATED FIRST FOLD LINE SO THAT EACH SIDE WALL IS FORMED INTO A FLAP, AT LEAST ONE OF SAID FLAPS BEING THUS FORMED WITH A RE-ENTRANT FOLD ADJACENT SAID SECOND FOLD LINE, WHICH RE-ENTRANT FOLD FORMS FROM AN OUTER PORTION OF SAID FIRST TRIANGULAR FOLD PIECE A SECOND TRIANGULAR FOLD PIECE, THE OUTER SURFACE OF SAID SECOND PIECE BEING IN FACING RELATIONSHIP TO AN ADJACENT PORTION OF SAID FIRST PIECE, WHICH ADJACENT PORTION COMPRISES A THIRD PIECE, SAID BACK WALL OVERLAPPING SAID FRONT WALL SO THAT THERE IS PROVIDED FROM SAID CLOSURE PORTION AN UNDERLAP PIECE AND AN OVERLAP PIECE, THE INNER SURFACE OF SAID OVERLAP PIECE AND THE OUTER SURFACE OF SAID UNDERLAP PIECE EACH BEING A BONDING SURFACE, (B) LIFTING FROM SAID UNDERLAP PIECE THE PORTION OF SAID OVERLAP PIECE WHICH IS FURTHER FROM THE BASE PORTION OF SAID BACK WALL, WHILE HOLDING AGAINST SAID UNDERLAP PIECE THE PORTION OF THE OVERLAP PIECE WHICH IS NEARER THE BASE PORTION OF SAID BACK WALL, (C) APPLYING AN ADHESIVE TO AT LEAST ONE OF SAID BONDING SURFACES AND TO THE OUTER SURFACE OF AT LEAST ONE OF SAID SECOND AND THIRD TRIANGULAR PIECES, AND BRINGING SAID BONDING SURFACES INTO CONTACT AND BRINGING INTO CONTACT SAID SECOND AND THIRD TRIANGULAR PIECE SO AS TO BOND SAID UNDERLAP PIECE TO SAID OVERLAP PIECE AND BOND SAID SECOND AND THIRD TRIANGULAR PIECES ONE TO ANOTHER. 